How Shifting Your Expectations about Food Can Help You Lose Weight

    A. If you are craving a satisfying dish but trying to be careful about your weight, few things are more dispiriting than reading the 'healthy' options on a food menu. Words like 'light', 'wholesome', 'skinnylicious', 'sensible', 'mild'—the adjectives that often accompany low-fat, low-carb options—hardly prepare you for a pleasurable meal. One obvious consequence is that it makes the foods seem less desirable, so you may be more tempted by indulgent choices: the 'rich', 'flavourful', 'delicious' dishes. But the influence of these words can stretch far beyond our immediate decision-making.
    B. The way we think about food can powerfully influence our satiety (饱腹感) long after we have finished eating, and thanks to the mind-body connection, it can even shape our hormonal responses and the meal's passage through the gut. As a result, our expectations around food can determine whether we will experience greater hunger pangs (饥饿感) afterwards and find it harder to resist snacking later in the day. And this is all down to the sense of deprivation created by the way the food was described, irrespective of the number of calories actually consumed.
    C. As I describe in my book The Expectation Effect, there are many ways to change our food mindsets, and they all centre on the idea that pleasure is an essential ingredient for any weight-loss regime. As paradoxical as it may seem, cultivating an indulgent attitude to food may be the best way to control your waistline.
    D. It was a man called Henry Molaison who provided some of the first clues to the ways our mind can influence our appetite. In the early 1950s, Molaison underwent experimental brain surgery to treat epilepsy (癫痫), but the operation caused irretrievable damage to his hippocampus (海马体——大脑中被认为是感情和记忆中心的部分). As a result, he could no longer form new memories, leading him to live in the 'permanent present tense', in the words of the neuroscientist Suzanne Corkin.
    E. To test whether his memory deficit would change his eating behaviour, the scientists performed a dinner-time experiment. After he had finished his meal, they cleared the table, and, within a minute, offered another plate of food. Amazingly, he ate nearly all of it—and, despite having consumed almost twice as much as normal, he reported only a moderate increase in his satiety.
    F. How could this be? There is little doubt that appetite is influenced by 'bottom-up' signals in the digestive system, such as a feeling of stretch in the muscles of the gastrointestinal (胃肠的) tract, and feedback from chemical sensors that can detect the presence of nutrients. The experiences of people with amnesia (健忘症) like Molaison, however, suggest that we also rely on 'top-down' sources of information—such as our memories of what we have eaten—to make sense of those cues, create the overall feelings of satiety and hunger, and to control subsequent food intake.
    G. Amnesia may offer extreme examples of these processes in action, but further research has shown that we are all susceptible to top-down influences on our appetite. Even mild forgetfulness seems to increase someone's chances of overeating, while prompts to recall a previous meal curb people's snacking.
    H. In one notable experiment, Suzanne Higgs at the University of Birmingham, U. K., invited a group of students into her lab to perform a taste test on some cookies, which, after completing a couple of questionnaires, they were free to consume. Higgs found that prompting the subjects to remember their lunch, by spending a few minutes describing what they had eaten, caused them to eat about 45 per cent less—around four cookies—than participants who wrote about their general thoughts and feelings, rather than their meal memory. This wasn't the case for participants who wrote about a meal from the day before—a more distant event that would have little effect on their feelings of satiety in the moment. Instead, it was expectations of current satiety, based on the recent memory, that mattered.
    I. Aside from memory, other contextual factors seem to shape our expectations of satiety, including the information we are given about a meal's contents. Researchers at the University of Aberdeen, U.K., invited 26 people for an omelette (煎蛋卷) breakfast on two occasions. Before they ate, participants were shown the ingredients. On one occasion, they were shown two eggs and 30 grams of cheese; on the other, they were shown four eggs and 60 grams of cheese.
    J. In reality, the participants all ate the same portions—three eggs and 45 grams of cheese—for both breakfasts. But the initial presentation did affect their subsequent appetite. People who had seen the smaller pile of ingredients subsequently ate more pasta from a buffet at lunchtime than those who believed they had already consumed a hearty meal.
    K. Of course, we don't always get to see the original ingredients in meals, especially in ready-made food, but labelling can influence our appetite through similar mechanisms. Many people associate the word 'healthy' with 'unfulfilling', for instance, which reduces their expected satiety. When a group of study participants were each given a 'healthy' chocolate-flavoured protein bar, they subsequently felt hungrier than people who had eaten the same bar when it was labelled 'tasty'. Indeed, the association was so strong that they felt hungrier than people who had eaten nothing at all.
    L. We don't yet know the full consequences of our food mindsets, besides their role in shaping appetite. But it is possible that these hormonal and neurological changes also determine how quickly the body burns calories or stores them as fat. If so, they could affect our weight. There are plenty of ways that we can start to apply this research ourselves. Many weight-control plans involve some form of calorie restriction, and a number of psychological principles can ease that process.
    M. If you are looking to lose weight, one easy step would be to avoid liquid calories. Multiple studies show that we expect liquids to be less satisfying than solid foods, even if they have the same calorie content. You may feel fuller after eating pieces of fruit than after drinking a smoothie (沙冰), for example. High-sugar sports recovery drinks are a particular example of something that contains more calories than your body would expect. The liquid form, combined with the health-focused labelling, means that these drinks are even less likely to reduce your appetite than solid food, so you may try to make up for the perceived deficit with snacking. The same goes for meal replacement shakes and smoothies that are billed as providing a balanced meal in a drink, and often touted as 'light' or 'low carb'.
    N. A second step would be to pay more attention to the taste and textures of what you are eating. It can be tempting to think, if you are on a diet, that you have to sacrifice your enjoyment of food, but the research on mindsets shows that excitement and anticipation of meals matters more, not less, if you are trying to lose weight. A meal should feel more satisfying if you choose foods with more intense flavours and make an effort with the presentation so the meal feels like a treat. According to this research, the very worst thing you can do is to eat something insipid (淡而无味的) that leaves you feeling deprived, just because it has slightly fewer calories than a more appetising option. You will just want to eat more.
    O. Ultimately, if you want to reduce how much you are consuming, the aim should be to realise that you can get all the pleasure you need from fewer mouthfuls, so that you choose a small portion and feel less tempted to snack later on. Whether you are eating a salad or a chocolate bar, a sense of celebration will help you to control your calorie intake.  

    A meal can become more gratifying if foods have more intense flavours and are presented with some efforts.

    Some foods with 'healthy' labels lower many people's expectations of satiety, for the word 'healthy' reminds them of 'unsatisfactory'.

    It seems that people are more likely to eat too much even if they suffer a mild loss of memory about a previous meal, but their appetite for snacks can decrease if they are reminded of that meal.

    Calorie restriction is required in some weight-control plans, and some psychological principles can make the process easy.

    There is nothing more frustrating than reading the 'healthy' choices on a food menu when you desire to enjoy a satisfying meal but try to control your weight meanwhile.

    Although it may sound paradoxical, developing a sense of indulgence about food may be the best way to achieve weight-control goals.

    In one famous experiment, the participants who were asked to describe their recent meal tended to eat less cookies than those who just took down their general thoughts and feelings.

    An experiment about food-consuming at dinner time was conducted by the scientists, so as to find out whether memory deficit had some effects on one's eating behaviour.

    People's expectations of satiety may be influenced by information about what are included in a meal before they eat.

    Our expectations about food can have a great impact on our sense of hunger and resistance to snacks sometime after we have finished eating.